ZestyCoach rewrites the female fitness formula
Addressing a $97 billion femtech market, ZestyCoach provides a personalized, comprehensive health experience rather than the fragmented, male-oriented advice often found in traditional fitness apps.
What happens when you combine a young entrepreneur’s lifelong passion for fitness with a computer science degree and the robust startup resources of East Tennessee?
You get ZestyCoach, an AI-driven platform designed to help ambitious women optimize their health through the lens of female physiology – and it’s the brainchild of a University of Tennessee, Knoxville student.
We sat down with founder Bella Matasic to discuss her entrepreneurial journey and the mission behind the app.
Entrepreneurial from the start
If you have seen Matasic, you’re probably already thinking that she is rather young for an entrepreneur. In that case, it may surprise you that ZestyCoach is not even her first startup.
Her first venture, a marketing startup she launched at 19, handled videography and web design. While that business is still active, Matasic exited daily operations two years ago to go all-in on ZestyCoach.
“I didn’t even know entrepreneurship was an option at first. I was never exposed to it until I was on the bus one day in high school, and I met someone who had a lawn care business as a kid, and I was like, ‘Wait, this is a thing that we can do?’ But as soon as I learned it was an option, I knew it was for me,” said Matasic.
Her biggest takeaway for aspiring founders? It is not as scary as it seems because people genuinely want to help you.
“I would not be anywhere near where I am today without the help of other people. It’s crazy,” she noted. “Even just the UT Anderson Center for Entrepreneurship and Innovation (ACEI). Those guys really help you out in your journey. People along the way have really shaped how I approach relationships and conversations.”
The mission: Listening to biology
As a longtime athlete, Matasic recognized a fundamental flaw in the fitness industry: most systems are designed for men and applied to women as an afterthought.
“Women, from a biological standpoint, are different from men down to a cellular level,” Matasic explained. “The way we train, the way we eat, how we time our eating, the way we time our workouts – it all matters. Even our gut health is physiologically and biologically different. We should have a product that gives us a platform that makes us actually feel heard instead of platforms that make us feel like we’re doing something wrong.”
ZestyCoach differentiates itself by syncing fitness and nutrition recommendations with individual hormonal cycles, something other platforms tend to overlook.
As the app has been in the development phase, Matasic has been the primary tester of the platform. Nevertheless, the results have been transformative for her.
“The biggest win for me has been training,” she said. “What I had a very hard time with was honestly not eating enough carbs, and I would just restrict myself massively. Once I followed the training plan and learned the way I was supposed to eat, I started immediately seeing results.”
Scaling personalization through AI
Developing the app over the last 18 months, Matasic faced the challenge of making this tailored coaching accessible. She found the answer in artificial intelligence.
“The whole idea is your coach has a bunch of flavor and personality, which is why it has the word ‘zest’ in the name. It also coaches you along your way, hence why the word ‘coach’ is also in the name,” Matasic said. “We couldn’t do coaching at scale without using AI for this.”
While AI is a critical piece of this app, Matasic is serious about data protection and user safety. The app includes guardrails regarding prompting and temperature settings to ensure the AI remains within specific guidelines.
“Mental health is a huge part of your overall health. If there’s any sort of conversation with your coach that brings up mental health, we have the necessary numbers in place and direct you to the right channels,” she added.
What’s next
The app is set to launch its beta phase in mid-April, targeting women 18 to 30. By the end of the month, Matasic plans to have the app live in the Apple App Store, with plans to expand into support for menopause and perimenopause.
As the app goes to market, Matasic is also embarking on a new professional chapter after her graduation this May. She is moving to Jacksonville, Florida, to join the AI Agentic team at CSX, where she will help educate their workers on AI implementation.
“I’m originally from Charlotte, NC, but I moved here for school. Tennessee has become home,” Matasic said. “The people are amazing and it is truly beautiful. From a business standpoint, if you’re gonna build a business anywhere, I wholeheartedly believe it should be in Tennessee.”
Matasic has bootstrapped the project thus far but remains open to funding support as she continues to optimize ZestyCoach from afar.
While her next role takes her to Florida, she has not ruled out a return to Tennessee for a future venture.
Follow ZestyCoach on Instagram.
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